Charles Darwin first explained the principles of sexual selection in his controversial book The Descent of Man (1871). Ever since then, people have wanted to tinker with human evolution via artificial sexual selection. Dictators, mad doctors, and crazed social scientists have proposed — and even carried out — human breeding experiments aimed at improving the species. For some definition of "improving." Here are five of the most bizarre and tragic experiments with human evolution from the last century.

In the late 1960s, Romanian dictator Ceausescu decided that the population of his country needed to grow much larger to provide strapping workers for industrial labor. First he tried to reward women who had several babies, but that program didn't work quickly enough. So in 1966, he outlawed abortion. Women were forbidden from using contraception, and underwent fertility checks at work. In 1967, the birth rate in the country doubled. The children born that year were called Decreteii, or children of the decree. Many suffered or died young because they were unwanted or had been born under adverse circumstances.

Clonaid is a company that purports to be engaging in human cloning, specifically to change the human species. They were embroiled in scandal when it was revealed that many Clonaid "scientists" were members of the Raelian cult (or religion, depending on how you feel about it) that believed humans were descended from cloned aliens. Scientists from Clonaid claim to have cloned a human, though they offer no concrete proof. So far, they have had zero impact on human evolution, but get points for trying to achieve evolutionary intervention via publicity.